1. Field of the Invention
The present invention relates to an ink cassette for holding an ink ribbon for use in a thermal transfer printer, a supply container for the ink ribbon, and a method of attaching the ink ribbon to the ink cassette. More particularly, the present invention relates to a technique for attaching an ink ribbon to an ink cassette easily and reliably, and a technique for reducing the running costs of a printer.
2. Description of the Background Art
FIGS. 14 and 15 are an external view and an exploded perspective view, respectively, of a conventional ink ribbon cartridge (also referred to simply as a xe2x80x9ccartridgexe2x80x9d) 59P for use in a thermal transfer printer. The cartridge 59P is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-74378 (1990).
An ink ribbon 3P stored in the cartridge 59P is wound around a supply bobbin 1P for a predetermined length from a first end thereof, and is fixed at its second end to a take-up bobbin 2P with a double-faced tape or the like. The ends of the bobbins 1P and 2P are placed on bobbin supports 55P, 56P, 57P and 58P, respectively, of a cartridge body 51P. A cartridge cover 52P is placed to cover the bobbins 1P and 2P. The cartridge body 51P and the cartridge cover 52P are bonded at their outer peripheral parts by ultrasonic welding or the like and fixed to each other. In the cartridge 59P, the ink ribbon 3P is exposed or uncovered from a window of the cartridge 59P formed by an opening 53P of the cartridge body 51P and an opening 54P of the cartridge cover 52P. The ink ribbon 3P, while being stored in the cartridge 59P, is mounted in a printer.
FIG. 16 is a schematic view for illustrating a method of printing using an ink ribbon in a thermal transfer printer. In the printer, a printing medium 62P in sheet form and the ink ribbon 3P exposed from the window are overlaid on a platen 61P, as shown in FIG. 16. A thermal head 60P having a plurality of small heat generators (not shown) applies pressure and heat to transfer a dye from the ink ribbon 3P to the printing medium 62P in sheet form. This produces an image on the printing medium 62P in sheet form.
A direct touch of a user""s hand on the ink ribbon 3P causes sebum on the user""s hand to adhere to the ink ribbon 3P, giving rise to transfer imperfection. A wrinkle in the ink ribbon 3P also results in transfer imperfection. However, the cartridge 59P allows the mounting of the ink ribbon 3P in the printer without the direct touch of foreign matter on the ink ribbon 3P.
More specifically, the position of the supply bobbin 1P supported by the bobbin supports 55P and 56P is designed so that the ink ribbon 3P prior to use which is wound around the supply bobbin 1P is floating in the air inside the cartridge 59P. Likewise, the ink ribbon 3P after use is also held floating inside the cartridge 59P.
The conventional ink ribbon cartridge 59P in which the cartridge body 51P and the cartridge cover 52P are bonded and fixed to each other as described above is difficult to disassemble. For replacement and discard of the ink ribbon 3P after use, the whole cartridge 59P with the ink ribbon 3P stored therein is required to be replaced and is discarded. Further, because of the difficulty in disassembling, it is impossible to reuse the cartridge body 51P and the cartridge cover 52P. The result of these disadvantages is the increased price of the conventional cartridge 59P.
Furthermore, the conventional ink ribbon 3P is not only enclosed by the cartridge body 51P and the cartridge cover 52P but also is contained in a plastic case or a corrugated cardboard carton during distribution. Thus, the materials enclosing the ink ribbon 3P accordingly increase the cost and price of the cartridge 59P.
The use of the conventional cartridge 59P thus presents the problem of increased running costs of the printer.
A first aspect of the present invention is intended for an ink cassette for holding an ink ribbon set, the ink ribbon set having a pair of bobbins each including a rod-shaped body, and an ink ribbon having a first end fixed to one of the bobbins and a second end, the ink ribbon, including the second end, being wound around the other of the bobbins. According to the present invention, the ink cassette comprises: a first part and a second part arranged in parallel with each other, each of the first and second parts including an elongate portion having bobbin holders for holding a corresponding one of the bobbins at respective longitudinal end portions in a longitudinal direction thereof, wherein each of the bobbin holders includes a pair of arms, the pair of arms defining a linear groove (or notch) extending in a direction intersecting the longitudinal direction, and wherein all of the grooves are placed in the same orientation, whereby each of the bobbins is received in a corresponding pair of the grooves and held around its axis.
Preferably, according to a second aspect of the present invention, in the ink cassette of the first aspect, each of the arms is flexible, and each of the grooves includes a portion having a width less than a diameter of a shaft of each of the bobbins.
Preferably, according to a third aspect of the present invention, in the ink cassette of the first or second aspect, there is a difference in width between at least one pair of the grooves included among two pairs of the grooves arranged in a direction in which the first and second parts are arranged, and there is a difference in width between a pair of the grooves possessed by each of the first and second parts.
Preferably, according to a fourth aspect of the present invention, in the ink cassette of any one of the first to third aspects, the first part has an alignment mark affixed to an opposite side from an opening of the grooves.
A fifth aspect of the present invention is intended for an ink ribbon supply container for storing an ink ribbon set therein, the ink ribbon set having a pair of bobbins each including a rod-shaped body, and an ink ribbon having a first end fixed to one of the bobbins and a second end, the ink ribbon, including the second end, being wound around the other of the bobbins. According to the present invention, the ink ribbon supply container comprises: a container body recessed in shape and sized to allow the ink cassette as recited in any one of the first to fourth aspects to enter the recessed container body, with the ink cassette assuming a position such that a plane defined to include the elongate portions of the first and second parts is in face-to-face relationship with a bottom part of the recessed container body; and a first bobbin support and a second bobbin support both provided in the recessed container body for supporting the bobbins laid down in the recessed container body respectively and for supporting the bobbins in parallel with each other in a position of an approximately equal depth in the recessed container body.
Preferably, according to a sixth aspect of the present invention, in the ink ribbon supply container of the fifth aspect, a side portion of the recessed container body functions to guide the ink cassette so that the groove of each of the bobbin holders is in face-to-face relationship with a corresponding one of the bobbins supported by the first and second bobbin supports when the ink cassette assuming the position enters the container body.
A seventh aspect of the present invention is intended for a method of attaching an ink ribbon to an ink cassette. According to the present invention, the method comprises the steps of: (a) preparing the ink cassette as recited in any one of the first to fourth aspects; (b) preparing the ink ribbon set stored in the ink ribbon supply container as recited in the fifth or sixth aspect; (c) overlaying the ink cassette on the ink ribbon set, with the groove of each of the bobbin holders in face-to-face relationship with a corresponding one of the bobbins; and (d) applying pressure toward the ink ribbon set to the ink cassette to insert each of the bobbins into a corresponding pair of the grooves.
In accordance with the first aspect of the present invention, the ink ribbon (set) is easily attached to the ink cassette by inserting (forcing) the bobbins into the grooves of the bobbin holders in a direction from the opening end of the grooves to the bottom part thereof. Additionally, since all of the grooves are in the same orientation, the two bobbins are simultaneously inserted into the grooves only by placing the bobbins in face-to-face relationship with the corresponding grooves and then pressing the ink cassette inwardly in the opening direction of the grooves. A user can attach the ink ribbon (set) to the ink cassette without touching the ink ribbon.
Further, the ink cassette can be reused by removing the ink ribbon (set) after use from the ink cassette. That is, only the ink ribbon set is replaced. This reduces the running costs of a printer.
In accordance with the second aspect of the present invention, the bobbins inserted in the grooves are prevented from disengaging from the grooves. The arms which are flexible are distorted and widened, and thus do not hinder the insertion of the bobbins.
In accordance with the third aspect of the present invention, the ink cassette is prevented from being mounted in an improper orientation.
In accordance with the fourth aspect of the present invention, the user can find the mounting orientation of the ink cassette by the alignment marks. This prevents the ink cassette from being mounted in an improper orientation. Additionally, the alignment marks affixed to the opposite side from the opening of the grooves facilitate and ensure the attachment process.
In accordance with the fifth aspect of the present invention, the ink ribbon (set) is easily attached to the ink cassette by overlaying the ink cassette on the ink ribbon set stored in the ink ribbon supply container and forcing the ink cassette toward the ink ribbon. Additionally, the bobbin supports support the ink ribbon (set) in a predetermined position, thereby eliminating the need for the user to take the ink ribbon (set) out of the ink ribbon supply container and to grasp the ink ribbon (set). In other words, the user can perform the attachment process without touching the ink ribbon.
Unlike a conventional ink ribbon cartridge in which an ink ribbon set and an ink cassette are integrated together, the supply container according to the fifth aspect of the present invention allows the supply of only the ink ribbon set, to reduce materials and the like enclosing the ink ribbon during distribution or supply, thereby making the ink ribbon available at low prices. Therefore, costs and prices are reduced, and consequently the running costs of the printer is reduced.
In accordance with the sixth aspect of the present invention, a face-to-face relationship is easily and reliably established between the grooves of the respective bobbin holders and the bobbins stored in the ink ribbon supply container.
In accordance with the seventh aspect of the present invention, the ink ribbon (set) is easily attached to the ink cassette. Additionally, the user need not take the ink ribbon (set) out of the ink ribbon supply container and to grasp the ink ribbon (set). Therefore, the user can perform the attachment process without touching the ink ribbon.
It is therefore a primary object of the present invention to provide an ink cassette and an ink ribbon supply container which are capable of attaching an ink ribbon thereto easily and reliably, and of reducing the running costs of a printer.
It is another object of the present invention to provide a method of attaching an ink ribbon to an ink cassette by the use of the ink cassette and the ink ribbon supply container which attain the primary object.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.